Blank for manufacturing commutator-bars.



A. E. DOMAN. BLANK FOR MANUFACTURING COMMUTATOR BARS.

APPLICKHON FILED JULYQ, L9H- Patented Oct. 22, 1918 I g Iuvsfi-ran ZMMUUNITED STATESVPATENT OFFICE. 4

ALBERT E. DOMAN, onnnnmnon. NEW Yoax, assrenon, nrifisnn SSIGNMENTS, roDYNETO nrncrarc conrom'rron, or srn n cosn, NEW Yoax, a co'nrona'rron OFNEW YORK.

Specification of Letters Patent.

BLANK son manurao'runmo comnu'ra'ron-nans.

Patented Oct. 22, 1918.

. Original application filed December 26, 1916, Serial No. 138,971.Divided and this application filed July 9, 1917. Serial No. 179,485.

To all whom'it may concern:

Be it known that I, ALBERT E. DoMAN, a

citizen of the United States of America, and resident of Elbridge, inthe county of On0n-- Bars, of which the following, taken in connectionwith the accompanying drawings,

a full, clear, and exact description.

Thisinvention relates to certain improve ments in the manufacture ofcommutators and parts thereof and in the blank from which the bars orsegments thereof are made and is a divisionof my copending application,Ser. No. 138,971 filed Decembe 26, 1916. v a i The primary object of theinvention is to reduce the expense of raw materials, as copper, and thecost of manufacture by forming the raw materials preferably in long,cold drawn strips tapered laterally from a cen-' tral portion or formedwith a double bevel so that the bars, with suitable integral tangs, maybe punched from the strips with but slight wasteof material, the angleor bevel of the strip being of such degree as to correspond with arequired angle when a predetermined number of bars or segments are, to(lie. nested together to form a complete cyliner. I

Other objects and advantages will appear from the following descriptiontaken in connection with the accompanying drawings, in Which v Figure 1is a view of the blank of this invention from which the commutator barsor segments may be punched. v

Fig. 2 is a top plan view of the blank, the shape of the bars and themethod of punch-' ing being indicated. Fig. 3 is a view of a ment.

Fig. 4 is a cross section of a commutator as constructed from suchsegments. 1

The invention, as shown, comprises the blank -1-- which may preferablybe a relatlvely long, cold drawn strip of suitable material, as copper,having a central substantially plane horizontal portion 2 with sideportions 3- and 4-- tapered or.

beveled in opposite directions therefrom.

complete bar or seg Both sides of the blank are symmetrical and of thesame conformation.

The side portions 3 and are disposed at the same angle relatively to theportion .1- and are of equal width, the angle of disposition of theoutwardly converging portion .-3 or the outwardly converging portion 4:-being of such a ,de-

'gree' as is required in the manufacture of a complete cylinder from apredetermined number of similarly. shaped nested bars or segments. Witha commutator constructed .of thirty-three bars or segments, as hereillustrated, the angle of disposition of the outwardly converging sideportions 4- or the outwardly converging side portions .3 isapproximately 10, 54', 32". The angle of disposition of each beveledportion -4- or each beveled portion 3 and the central portion -2' beingapproximately form the-cylindrical portion of the commutator.

- From the strip 1- coimnutator bars 5- can be punched or cut with amini mum waste of material and with a minimum cost of production in themanner shown in Fig. 2. The. bar is punched along lines 8,

9 and 10, the line 8 extending from one side of the bar to the centralportion of the bar, said line being spaced f rom the ad] acent end ofthe strip 1- a distance equal to the de-- sired Width of tang 6-. Theline --9 extends from the inner termination of line -8- longitudinallyand centrally of the strip -1-a distance equal to the desiredwidth ofthe body of the commutator bar;

adapted to form the cylindrical portion of the commutator. The line -10-extends from the termination 'ofline to the'edge of thebar opposite thatat which the line -8- terminates. Preferablyportions -13 and -14.- arecut from the edgeof the bar to form, in connection with body 7-,- anintegral wedgeshaped member -11- adapted to receive suitable, usual andwell'known means, as ring members, for holding the segments in nestedposition in the completed commutator. These portions 13- and 14- whichare cut out to form the wedgeshaped member -11 are the only wastematerial in constructing the commutator bars.

In order to form the second commutator bar, the strip is punched alongline ;'l2- and the portions -:-13 and 'l4.- are preferably punched outto form the wedgeshaped member 11. The line 12 is spaced from the line+10- a distance equal to the desired Width of tang 6. By this method. ofcutting or punching, two complete commutatorbars are cut from a strip ofmaterial equal in width to the radial length of a commutator bar andequal in length to the complete width of a commutator bar plus the widthof one tang.

The bars, as shown, may be mounted upon I a suitable sleeve or core -15and may be held in assembled position .upon the sleeve inany suitableand usual manner. 7

Although I have shown and described one particular construction andexact methodas constituting a preferred embodiment of "this invention,it will be apparent that changes and alterations maybe made in the exactform of the commutator bar and the exact method of punching the samewithout departing from the spirit of this invention asset forth in theappended claims.

What I claim is: 4

1. A blank for manufacturing commutator bars consisting of a relativelythin wide strip of suitable material tapered laterally from anintermediate portion toward its opposite edges, the opposite flatsurfaces of said tapered portions forming substantially the bl equalangles with the central plane connecting opposite edges of the blank. 2.A blank for manufacturing commutator bars consisting of a relativelythin wide strip of suitable material, the width of the same beingsubstantially equal to the maximum radial width of the commutator barwhen assembled, said bar tapered from an intermediate portion towardopposite edges, the angular disposition of the outwardly convergingwallsofsaid side portions correspondingto the required angle forproducing a complete cylinder from a predetermined number of similarsubstantially radially arranged segments.

3. A blank for manufacturing commutator bars consisting ofa relativelythin wide strip of suitable material having a central plane portion withopposite sides substantially parallel and opposite side portions havingtheir opposite walls converging outwardly,

{the opposite walls ofsaid side portions formingsubstantially equalangles with the central lane connecting opposite edges of .4. Ablank'for manufacturing commutator bars, consisting of an elongated striof suitable material having a central, 'plime portion with oppositesides substantially parallel and opposite side portions having theiropposite walls conver 'ng outwardly,.

the angle of disposition o the outwardly converging walls of; each sideportion corresponding to the required angle for' producing-a com letecylinder from a predetermined num r of similar nested segments.

In witness whereof I have hereunto set my hand this 27th da of June,1917.

J. D. .FmMMma, .Manr H. Gmcn.

